首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   399篇
  免费   3篇
  2020年   5篇
  2018年   11篇
  2017年   13篇
  2016年   9篇
  2014年   11篇
  2013年   15篇
  2012年   22篇
  2011年   18篇
  2010年   5篇
  2009年   9篇
  2008年   21篇
  2007年   18篇
  2006年   17篇
  2005年   12篇
  2004年   9篇
  2003年   15篇
  2002年   6篇
  2001年   8篇
  2000年   10篇
  1999年   3篇
  1998年   2篇
  1996年   2篇
  1992年   13篇
  1991年   14篇
  1990年   7篇
  1989年   13篇
  1988年   9篇
  1987年   5篇
  1986年   4篇
  1985年   8篇
  1984年   7篇
  1983年   2篇
  1982年   2篇
  1981年   3篇
  1980年   2篇
  1979年   2篇
  1978年   6篇
  1977年   5篇
  1976年   3篇
  1975年   7篇
  1974年   8篇
  1973年   5篇
  1972年   7篇
  1971年   6篇
  1970年   4篇
  1969年   3篇
  1968年   4篇
  1967年   3篇
  1966年   1篇
  1965年   2篇
排序方式: 共有402条查询结果,搜索用时 15 毫秒
51.
The concentration of soluble epoxide hydrolase (sEH) protein was studied in renal medulla of adult rats from hypertensive ISIAH strain and normotensive WAG strain. The sEH is a key enzyme in metabolism of epoxyeicosatrienoic acids capable of activating endothelial NO-synthase and nitrogen oxide formation, and therefore being vasodilators. An increase in the sEH protein concentration (that we found) allows one to assume that the oxidative stress is increased in the renal medulla of hypertensive rats, and the bloodflow is decreased.  相似文献   
52.
Using Fura-2AM microfluorimetry, it was shown for the first time that neuroleptic chlorpromazine causes intracellular Ca2+ concentration increase in macrophages due to Ca2+ mobilization from intracellular Ca2+ stores and subsequent Ca2+ entry from the external medium. Chlorpromazine-induced Ca2+ entry is inhibited by La3+ and 2-aminoethoxydiphenyl borate and is associated with Ca2+ store depletion.  相似文献   
53.
54.
AIM: Evaluation of the diagnostic value of pheno- and genotypic characteristics of B. cepacia strains collection. MATERIALS AND METHODS: Phenotypic and genetic methods of identification and differentiation of 25 strains of the B. cepacia complex. RESULTS: Polyphasic taxonomic approach utilizing multiple diagnostic tests was used for accurate identification of Burkholderia species. Algorithm for identification of microorganisms from the B. cepacia complex was developed. CONCLUSION: Combined use of phenotypic and molecular genetic tests, such as recA gene PCR, is recommended for differentiation of the B. cepacia complex genomovars.  相似文献   
55.
The synthesis of starburst polymer–protein conjugates on the basis of bovine serum albumin and horseradish peroxidase was performed with the aim to study the possibilities of regulation of the immune response against the components of the conjugates. These polymers had one-point binding between the protein and the modifying carbon-chain polymer that contained 1-vinyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (a salsolinol analogue) or bradykinin (peptide hormone) residues in its carbon chain. Changes in the chemical nature of the carbon-chain part of the polymer–protein conjugate were shown to increase or decrease the level of antibody production both against the low-molecular compounds attached to the polymeric fragments and against the protein carrier.  相似文献   
56.
57.
KEGG spider is a web-based tool for interpretation of experimentally derived gene lists in order to gain understanding of metabolism variations at a genomic level. KEGG spider implements a 'pathway-free' framework that overcomes a major bottleneck of enrichment analyses: it provides global models uniting genes from different metabolic pathways. Analyzing a number of experimentally derived gene lists, we demonstrate that KEGG spider provides deeper insights into metabolism variations in comparison to existing methods.  相似文献   
58.
A significantly reduced gonadotropin and testosterone secretion is a well-described result of long-term administration of GnRH agonists in the male dog and cat. To date, no data are available about the duration of efficacy and the reversibility of treatment-induced effects after long-term treatment with a 4.7 mg deslorelin implant. Seven healthy male European Shorthair cats (3.2 ± 0.5 kg, 1–6 years) were treated with a 4.7 mg deslorelin implant. Blood samples (testosterone, T), testicular volume, penile spines, and mating behavior were recorded once weekly. Considering T > 0.5 ng/mL as the biological endpoint, mean duration of efficacy was 78.8 ± 12.9 weeks (range: 61.7–100.7 weeks) with T concentrations increasing rapidly after the last T less than 0.1 ng/mL (basal) (P < 0.0001), and pretreatment T concentrations being reached after 3 weeks. Testicular volume rapidly increased after the first increase of T (P < 0.001) with pretreatment testicular volume being reached after 6.9 ± 3.4 weeks (5–11 weeks). “Normal” libido reoccurred 88.7 ± 12.4 weeks after treatment, and “normal” mating behavior was observed even later. Fertile matings occurred 7 to 42 weeks after the last T less than 0.1 ng/mL with a mean of 4.0 ± 0.0 kittens, and 13.6 to 47.6 weeks afterwards testicular histology revealed normal spermatogenesis. The present data confirm that the use of slow-release GnRH-agonist implants containing deslorelin in tomcats represents an effective and safe reversible alternative for long-term contraception; however, as number of animals is low, further fertility trials are recommended.  相似文献   
59.
Seven new triterpene glycosides, erylosides R1 (1), T1 (3), T2 (4), T3 (5), T4 (6), T5 (7), and T6 (8) along with the known formoside (2) were isolated from the sponge Erylus formosus collected along the Caribbean coast of Mexico. Glycoside 1 was determined as a trisaccharide, glycoside 2 as a tetrasaccharide while glycosides 38 were hexasaccharide. Their carbohydrate chains were unprecedented and have never been found in oligosaccharides from other biological sources, except Erylus spp. Three carbohydrate chains in the glycosides 3 and 6, 4 and 7, 5 and 8 correspondingly are new. The glycosides 15 have penasterol as aglycone while glycosides 68 proved to be glycoconjugates of 24-methylene-14-carboxy-lanost-8(9)-en-3β-ol.  相似文献   
60.
The aim of the present study was to test for the efficacy of a slow release GnRH-agonist implant (4.7 mg deslorelin, Suprelorin®) in the male cat. Ten toms were implanted sc in the neck. Changes in testosterone (T) secretion, testicular size, body weight and behaviour (mounting, mating, urine marking) were monitored. T concentrations were significantly decreased (P < 0.0001) to basal levels (< 0.1 ng/mL) in 5 of 10 cats after 4 weeks and in all but one tom after 11 weeks (T < 0.1 ng/mL). In this respective tom only partial downregulation with T-values from 0.2 to 0.1 ng/mL was achieved until week 27. In weeks 28 and 32, T concentrations were below 0.1 ng/mL. Compared to pretreatment values, testicular volume was significantly decreased by about 60% in week 12 and about 73% after 36 weeks (P < 0.001). Penile spines disappeared 9.4 ± 1.0 weeks after treatment. Food intake was significantly increased during treatment period (P < 0.001). In all tomcats libido, mating behaviour and urine marking were significantly reduced (P < 0.0001) after an initial stimulation. In one tom, mating an oestrous queen on day 20 after implant administration resulted in pregnancy. Mating of another tom that had T-values between 0.1 and < 0.1 ng/mL since day 24 in week 8 revealed the presence of spermatozoa; however, this mating did not result in pregnancy.Subcutaneous implant administration was well tolerated by all tomcats without sedation or anaesthesia and no treatment related negative effects were observed.These results demonstrate the clinical efficacy of the 4.7 mg deslorelin implants (Suprelorin®) in the tom inducing all castration related effects.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号